Resumen de Effects of a dietary supplement on the incidence of acute respiratory infections in susceptible adults: a randomized controlled trial

María Fernanda Bernal-Orozco, Margarita Posada Falomir, Rafael Ortega Orozco, Elvia Elaonor Silva Villanueva, Gabriela Macedo Ojeda, Yolanda Fabiola Márquez Sandoval, Bárbara Vizmanos Lamotte

• español

  Introducción: aunque la suplementación de micronutrientes específicos puede mejorar determinados factores inmunológicos, han sido publicados pocos estudios sobre la combinación de micronutrientes con extractos herbales y la incidencia de infecciones respiratorias agudas (ARI) .

  Objetivos: evaluar el efecto de un suplemento alimenticio con micronutrientes y extractos herbales en la incidencia de ARI en adultos susceptibles, en enero-abril de 2012.

  Métodos: se realizó un ensayo clínico paralelo, aleatorizado, doble ciego, controlado con placebo. Se incluyeron adultos susceptibles a ARI, sanos en el momento de la evaluación, que firmaron un consentimiento informado y que no tomaban medicamentos. Completaron una historia clínica y se evaluó: peso, talla, signos vitales y de laboratorio. Se asignaron aleatoriamente para consumir durante 90 días el suplemento o un placebo. Los sujetos registraron diariamente si presentaban o no síntomas de ARI en un diario. En caso de enfermedad, se lo notificaron a los investigadores y el médico responsable confirmó la presencia de infección. Se utilizó la prueba exacta de Fisher para comparar la proporción de enfermos entre los grupos y se calculó el riesgo relativo y la diferencia de riesgos (p < 0,05 significativa).

  Resultados: de 59 sujetos incluidos, 45 (25 mujeres) completaron el estudio (21 del grupo suplementado y 24 del placebo). No hubo diferencias significativas al inicio entre grupos. Al finalizar la intervención, el grupo suplementado tuvo una menor incidencia de ARI en comparación con el placebo (57,1% vs 91,7%, p = 0,013, RR = 0,62, IC95% 0,42, 0,92).

  Discusión: en conclusión, el consumo de un suplemento a base de micronutrientes y extractos herbales puede disminuir la incidencia de ARI en adultos susceptibles.

• English

  Introduction: although supplementation of specific micronutrients may improve immunologic factors, few studies about the combination of micronutrients with plant extracts on the occurrence of acute respiratory infections (ARI) have been published.

  Objectives: to assess the effect of a nutritional supplement with micronutrients and plant extracts on the incidence of ARI in susceptible adults between January and April, 2012.

  Methods: a randomized, double-blind, parallel, placebo-controlled clinical trial was performed. Participants were adults susceptible to ARI who were healthy at the time of evaluation, signed informed consent forms and were not taking medication. They completed a medical history; weight, height, vital signs and laboratory analyses were assessed. Subjects were randomly assigned for consumption of the supplement or a placebo, for a 90 days period. Subjects made daily diary entries indicating the presence ARI symptoms. Those who became ill notified researchers and the attending physician confirmed the presence of an infection. Fisher’s exact test was used to compare the proportion of ill subjects between groups. Relative risk and risk difference were also calculated (p < 0.05 significant).

  Results: of 59 included subjects, 45 (25 women) completed the study (21 in the supplemented group and 24 in the placebo group). There were no significant differences at baseline between groups. After the intervention, the supplemented group had a lower incidence of ARI compared with the placebo group (57.1% vs. 91.7%, p = 0.013, RR = 0.62, 95%CI 0.42, 0.92).

  Discussion: the consumption of a supplement with vitamins, minerals and plant extracts may decrease the incidence of ARI in susceptible adults.